Fuse holder for accommodating wide range of lengths of cartridge-type fuses



I March 29, 1966 J. R. HOLLINS 3,243,551

FUSE HOLDER FOR ACCOMMODATING WIDE RANGE OF LENGTHS OF CARTRIDGE-TYPE FUSES FiledSept. s. 1964 46 FIG. 2

ul I INVENTOR JESSE A. Hall/N5 United States Patent 3 243 551 FUSE HOLDER FoRAccoMMoDATINo WIDE RiAJSlVGE 0F LENGTHS OF CARTRIDGE-TYPE F ES Jesse R. Hollins, 1059 E. 22nd St., Brooklyn, N.Y. Filed Sept. 8, 1964, Ser. No. 394,876 6 Claims. ((11. 200-119 This invention relates to a fuse holder for accommodating any one of a wide range of various different lengths of cartridge-type fuses and for connecting the fuse in-line in a vehicular electrical circuit.

Present day in-line fuse holders are designed to accommodate only one particular length of fuse or a narrow range of lengths of fuses. Standard size SFE fuses as well as commercial type 3AG glass fuses, however, vary in length from to 1 although all have a uniform diameter of A". For this reason, there are presently marketed fuse holders of a variety of set lengths each individually designed to fit and hold a cartridgetype fuse of one of various different lengths or of a narrow range of length-s. A short fuse requires a short fuse holder, a medium length fuse requires a medium length fuse holder, and so on.

It would be more convenient to have a single fuse holder that could accommodate any of the full range of lengths of cartridge-type fuses and incorporate any one of such fuses in-line in a vehicular electrical circuit. Such a fuse holder would receive any length fuse from the short 4 amp. length to the long 30 amp. length. Only the proper amperage fuse would have to be furnished to properly prevent electrical overloading and the fuse holder would remain the same regardless of the length of the fuse. If it should be desired to change the fuse capacity, the old fuse would be removed, the fuse holder adjusted and a new cartridge-type fuse of a different length substituted within the holder. Various amperage fuses are a common commodity and are readily available for this purpose. The necessity of replacing the entire fuse holder and the task of rewiring the new fuse assembly would be completely eliminated.

In my copending patent application, Serial No. 391,532, for In-line Fuse Holders filed August 24, 1964, there is disclosed a fuse holder for accommodating fuses of different lengths. Herein, I disclose another new and difierent fuse holder for the above purpose.

- spacing from one another.

It is the object of my present invention to provide an in-line fuse holder for cartridge-type fuses which can readily be adjusted to receive fuses of a Wide range of different lengths. The fuse holder is adjustable without requiring the use of hand tools and will firmly grip the fuse to insure electrical contact therewith regardless of the length of fuse being engaged. Further, the fuse holder will permit easy and speedy replacement of a blown fuse with a fresh one.

It is another object of my invention to provide a fuse holder of the character described having a minimum of parts, which is simple yet rugged in construction, which is long lasting in use, which can be mass produced and which is saleable at -a relatively low price.

In general, I provide a fuse holder of the charater described that includes an elongated hollow casing which encloses the body of the fuse and which is substantially coaxial with the fuse. An open end of the casing is detachably closed by a socket that receives the conductive cap on one end of the fuse. Separation of this socket from the casing permits access to the deep hollow interior of the casing and allows insertion of a fuse into the casing or replacement of one fuse with another. The socket carries an electrical contact which is arranged to abut the end cap of the fuse and to which is connected an insulated wire.

The other end of the casing is permanently closed except for a bore to permit passage of another insulated wire. This wire is connected to a second similar electrical contact within the casing and arranged to abut the other conductive cap of the fuse. At least one contact, and optionally both contacts, is biased into engaegment with its affiliated end cap of the fuse. As shown herein the electrical contact carried by the detachable socket is longitudinally fixedly supported relative to the casing by its socket, or is permitted a narrow range of longitudinal movement if it is backed by a spring. The second electrical contact is carried, in accordance with an essential feature of my invention, by an end wall, i.e. a false bottom, member which can be detachably fixed by positioning means at any selected one of several predetermined longitudinally spaced sites adjacent or variably spaced from the closed end of the casing. Said positioning means includes several groups of guide slots of different lengths oriented longitudinally on the interior of the casing and a group of mating lugs on the false bottom. Since the false bottom within the casing can thereby be fixed either nearer to or further from the detachable socket depending in which group of slots the lugs of the false bottom are engaged, the electrical contacts carried each by one of these parts are likewise variable in their The gap between the socket and the false bottom within the casing can be varied through a wide range and thus a variety of fuses of different lengths can be received by my fuse holder.

'Other objects of my invention will in part be obvious and in part will be set forth hereinafter.

My invention accordingly consists in the features of construction, combinations of elements and arrangements of parts which will be exemplified in the fuse holder hereinafter described and of which the scope of application will be indicated in the appended claims.

In the accompanying drawings, in which I have shown a possible embodiment of my invention,

FIG. 1 is an exploded view of the several components of my fuse holder;

FIG. 2 is a longitudinal axial cross sectional enlarged view of the fuse holder and accommodating a cartridgetype fuse;

FIGS. 3, 4 and 5 are transverse cross sectional views taken substantially along the lines, respectively, 33, 4-4 and 55 of FIG. 2; and

FIG. 6 is a longitudinal axial cross sectional view of the casing taken substantially along the line 6-6 of FIG. 1.

Refering now to the drawings, the reference numeral 10 denotes a fuse holder constructed in accordance with the teaching of my invention to accommodate fuses of a wide variety of lengths. The holder receives a cartridge-type fuse 12 and incorporates the fust in-line in a motor vehicular electrical circuit.

Typically such a fuse is elongated and includes a transparent dielectric hollow cylindrical body 14 and a pair of conductive end caps 16, each cap closing a different end of the fuse. Electrically connecting and supported between the caps 16 is a low resistance fuse link 18 which is designed to melt upon thepassage through the link of current in excess of a predetermined amperage.

The fuse holder 10 comprises an elongated hollow right cylindrical casing 20 which is coaxial with the fuse and encloses the body of the fuse. The casing in both its length and interior diameter is greater than corresponding dimensions of the longest fuse which the fuse holder can accommodate. The casing, as Well as any other nonconductive components of the holder, are typically formed from a conventional dielectric material, e.g. a thermosetting synthetic resin.

The casing 20 has an open enlarged end 22 of both larger interior and exterior diameter than the rest of the casing. In this enlarged end is detachably received a cup-shaped socket 24. The socket has its cup-shaped portion 26 facing the interior of the casing and the cupshaped portion 26 has an interior diameter large enough and the cup-shaped portion is deep enough to receive an end cap 16 of the fuse 12. The exterior diameter of the socket 24 is a slidable fit in the open end of the casing.

The socket 24 is detachably fixed to the open end of the casing 20 by a bayonet coupling. To this end, the socket carries two diametrically opposed radially outwardly protruding lugs 28 and the open enlarged end 22 of the casing has a pair of diametrically opposed inwardly opening slots 30 at the bottom end of each of which a retroverted branch 32 is transversely offset. The socket can be detached from the end of the casing for insertion or replacement of a fuse by rotating the lugs thereon out of'the branches and then sliding the socket along the slot until the lugs clear the open ends of the slots and the parts are separated in a conventional manner. The socket can again be fixed to the end of the casing in the reverse order of steps. To facilitate manipulation the exposed end of the socket is knurled as at 33.

An electrically conductive contact 34 is carried by and located against the back wall of the cup-shaped portion 26 of the socket 24. The face 40 of the contact abuts the affiliated end cap 16 of the fuse 12 and the contact has an axial collar 42 which intrudes into a through bore 44 in the socket. The bore 44 passes from the cupshaped portion 26 to the exterior end of the socket.

A stripped end of an insulated wire 46 is fixed within the collar, as by soldering or crimping, and passes through the bore 44 to the exterior of the socket. The wire 46 is adapted to be connected in-line into an electrical circuit.

The other end 48 of the casing 20 is closed except for a through-bore 50 which extends from the exterior to the interior of the casing.

Another electrical contact 52, similar in construction to the first-described contact 34, has a face 54 which abuts the other conductive end cap 16 of the fuse. It also has a collar 56 to which is electrically connected in a similar manner a stripped end of another insulated wire 58. This latter wire is also adapted to be connected in-lirie into an electrical circuit.

The contact 52 is supported by a cylindrical internal wall member, i.e. a false bottom 60, which has an outside diameter that slidingly matches the uniform inside diameter of the casing. 20. The false bottom 60 has a central bore 61 which is coaxial with and of the same diameter as the bore 50 in the closed end 48 of the socket. A compression coil spring 62 is interposed between the contact 52 and the floor of the false bottom 60 and is wound about the collar 56 and the end of the wire 58 connected to the collar. The coil spring 62 urges the contact away from the false bottom 60 and into abutment with the conductive bottom face of the end cap 16, and thereby biases both contacts into electrical connection with their associated end caps 16.

Positioning means selectively locates the false bottom in any selected one of several longitudinally spaced predetermined locations near the closed end 48 of the casing 20. Said means includes a group, e.g. two, although more may be employed, of diametrically opposed radially outwardly protruding lugs 63 fixed on the outside circumference of the false bottom 60 and three matching groups of straight facing parallel guide slots 64. The slots are formed in the interior cylindrical wall of the casing and each is parallel to the longitudinal axis of the casing. The slots which make up a group, e.g. two, of slots are coextensive and are diametrically opposed from one another. Each slot is of like rectangular transverse cross section and is suitably dimensioned to slidingly receive a lug 63 of the false bottom 60.

Each group of guide slots 64 initiates at an open end and runs from the interior of the enlarged open end 22 of the casing and terminates at a closed end short of the closed end 48 at a location longitudinally spaced from the closed ends of the other groups of slots. That is to say, one group of slots 64a is of relatively short length, another group of slots 64b is of relatively intermediate length and the third group of slots 640 is of relatively long length. Each of the groups of slots terminates at different distances from the closed end 48.

The slots of the different groups are circumferentially arranged within the casing in equiangularly spaced mutual relationship. As shown, with two slots in each group and three groups, the center-to-center spacing of the slots is The false bottom 60 is located longitudinally within the casing by the closed ends of any selected group of guide slots 64. The false bottom is positioned by sliding the lugs 63 along a group of slots until they abut the closed ends of said slots. Once in the slots, and with the socket 24 in place, the lugs and false bottom are urged toward the closed end of the casing by the coil spring 62.

To change the length of fuse which the holder can accommodate, the false bottom 60 is positioned at a different longitudinally spaced location adjacent the closed end 48 of the casing. To this end, the false bottom is slid out of a group of guide slots (in a direction toward the open end of the casing), is rotated until the lugs are in alignment with a different group of guide slots, and then its lugs are slid into said different group of guide slots in a direction toward the closed end of the casing. To accommodate a short fuse, the lugs 63 of the false bottom are placed into and come to rest at the closed ends of the short slots 64a; for a medium length fuse, the lugs are placed into and come to rest at the closed ends of the intermediate length slots 64b; and for a long fuse, the lugs are placed into and come to rest at the closed ends of the long slots 640.

The distance between the false bottom 60 and the socket 24 can thus be adjusted to provide three different gaps within the casing to accommodate cartridge-type fuses of a variety of ranges of lengths. However, since there are numerous sizes of fuses within each range of gaps, the coil spring 62 is quite long and strong so as to take up the difference in length between the length of the gap and the length of the fuse and to insure firm engagement and good electrical connection between the contacts 34, 52 and the end caps 16 of the fuse.

Although the present invention has been disclosed in connection with motor vehicle electrical equipment, it is to be understood that the same can be used with related equipment requiring fuse functions, as, for example, in the marine and aircraft fields.

It thus will be seen that I have provided a fuse holder which achieves the several objects of my invention and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, I claim as new and useful and desire to obtain by Letters Patent:

1. An in-line fuse holder for incorporating any one length cartridge-type fuse of a variety of lengths of such fuses into an electrical circuit, each such fuse having a body and conductive end caps, said holder comprising: an elongated casing having an open end and a closed end and receiving the body of the fuse, a socket, means detachably mounting the socket on the open end of the casing so as to permit selective access to the interior of the casing for replacement of or insertion of a fuse therein, a'first electrical contact carried by the socket and abutting and thus electrically engaging an associated end cap of the fuse, an internal wall member within the casing, positioning means locating the wall member in any selected one of several predetermined longitudinally spaced locations near the closed end of the casing, a second electrical contact supported by the wall member and abutting and thus electrically engaging the other end cap of the fuse, insulated wires each electrically connected to a different contact and adapted to be connected into the electrical circuit, and means biasing the contacts into engagement with the end caps of the fuse, the location of the wall member in any one of said predetermined locations varying the effective gap between the wall member and the socket within the sleeve, whereby to accommodate fuses of various lengths.

2. An in-line fuse holder as set forth in claim 1 wherein the positioning means includes a group of lugs project ing from the periphery of the wall member and plural groups of matching slots in the casing, said slots opening at the open end of the casing and the different groups of slots having closed ends at different distances from the open end of the casing.

3. An in-line fuse holder as set forth in claim 2 wherein there are two lugs on the wall member and two slots in each group of slots.

4. An in-line fuse holder as set forth in claim 2 wherein the open ends of the slots are in a common plane and wherein the closed ends of the slots of the different groups are in different common planes.

5. An in-line fuse holder as set forth in claim 2 wherein the biasing means constitutes a spring interposed between the wall member and the second electrical contact.

6. An in-line fuse holder as set forth in claim 2 wherein the casing has a deep hollow interior for fully receiving the fuse.

No references cited.

BERNARD A. GILHEANY, Primary Examiner. 

1. AN IN-LINE FUSE HOLDER FOR INCORPORATING ANY ONE LENGTH CARTRIDGE-TYPE FUSE OF A VARIETY OF LENGTHS OF SUCH FUSES INTO AN ELECTRICAL CIRCUIT, EACH SUCH FUSE HAVING A BODY AND CONDUCTIVE END CAPS, SAID HOLDER COMPRISING: AN ELONGATED CASING HAVING AN OPEN END AND A CLOSED END AND RECEIVING THE BODY OF THE FUSE, A SOCKET, MEANS DETACHABLY MOUNTING THE SOCKET ON THE OPEN END OF THE CASING SO AS TO PERMIT SELECTIVE ACCESS TO THE INTERIOR OF THE CASING FOR REPLACEMENT OF OR INSERTION OF A FUSE THEREIN, A FIRST ELECTRICAL CONTACT CARRIED BY THE SOCKET AND ABUTTING AND THUS ELECTRICALLY ENGAGING AN ASSOCIATED END CAP OF THE FUSE, AN INTERNAL WALL MEMBER WITHIN THE CASING, POSITIONING MEANS LOCATING THE WALL MEMBER IN ANY SELECTED ONE OF SEVERAL PREDETERMINED LONGITUDINALLY SPACED LOCATIONS NEAR THE CLOSED END OF THE CASING, A SECOND ELECTRICAL CONTACT SUPPORTED BY THE WALL MEMBER AND ABUTTING AND THUS ELECTRICALLY ENGAGING THE OTHER END CAP OF THE FUSE, INSULATED WIRES EACH ELECTRICALLY CONNECTED TO A DIFFERENT CONTACT AND ADAPTED TO BE CONNECTED INTO THE ELECTRICAL CIRCUIT, AND MEANS BIASING THE CONTACTS INTO ENGAGEMENT WITH THE END CAPS OF THE FUSE, THE LOCATION OF THE WALL MEMBER IN ANY ONE OF SAID PREDETERMINED LOCATIONS VARYING THE EFFECTIVE GAP BTWEEN THE WALL MEMBER AND THE SOCKET WITHIN THE SLEEVE, WHEREBY TO ACCOMMODATE FUSES OF VARIOUS LENGTHS. 